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Brominated flame retardants in the Australian population: 1993–2009
Chemosphere 89 (2012) 398–403
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Brominated flame retardants in the Australian population: 1993–2009 Leisa-Maree L. Toms a,b,⇑, Paula Guerra d, Ethel Eljarrat d, Damià Barceló d, Fiona A. Harden a, Peter Hobson e, Andreas Sjodin f, Elizabeth Ryan c, Jochen F. Mueller c a
Medical Radiation Sciences, Queensland University of Technology, Brisbane, Australia Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia c The University of Queensland, National Research Centre for Environmental Toxicology (Entox), Brisbane, Australia d Department of Environmental Chemistry, IDAEA, CSIC, Barcelona, Spain e Sullivan Nicolaides Pathology, Brisbane, Australia f Centers for Disease Control and Prevention, Atlanta, USA b
h i g h l i g h t s " PBDE and HBCD concentrations assessed from 16 year period in Australia. " HBCD detected in 70% of human milk samples, no temporal trend apparent. " PBDEs detected in 100% of human milk and human blood serum samples. " Trend of decreasing PBDE serum concentrations in children from 2002/03 to 2008/09. " No PBDE trend in adults – youth body burden better reflects recent exposure.
a r t i c l e
i n f o
Article history: Received 23 November 2011 Received in revised form 5 May 2012 Accepted 19 May 2012 Available online 28 June 2012 Keywords: HBCD Hexabromocyclododecane PBDEs Brominated flame retardants Blood serum Breast milk
a b s t r a c t Brominated flame retardants, including hexabromocyclododecane (HBCD) and polybrominated diphenyl ethers (PBDEs) are used to reduce the flammability of a multitude of electrical and electronic products, textiles and foams. The use of selected PBDEs has ceased, however, use of decaBDE and HBCD continues. While elevated concentrations of PBDEs in humans have been observed in Australia, no data is available on other BFRs such as HBCD. This study aimed to provide background HBCD concentrations from a representative sample of the Australian population and to assess temporal trends of HBCD and compare with PBDE concentrations over a 16 year period. Samples of human milk collected in Australia from 1993 to 2009, primarily from primiparae mothers were combined into 12 pools from 1993 (2 pools); 2001; 2002/2003 (4 pools); 2003/2004; 2006; 2007/ P 2008 (2 pools); and 2009. Concentrations of HBCD ranged from not quantified (nq) to 19 ng g 1 lipid while a-HBCD and c-HBCD ranged from nq to 10 ng g 1 lipid and nq to 9.2 ng g 1 lipid. b-HBCD was P detected in only one sample at 3.6 ng g 1 lipid while 4PBDE ranged from 2.5 to 15.8 ng g 1 lipid. No temporal trend was apparent in HBCD concentrations in human milk collected in Australia from 1993 to 2009. In comparison, PBDE concentrations in human milk show a peak around 2002/03 (mean P 1 lipid) and 2003/04 (12.4 ng g 1 lipid) followed by a decrease in 2007/08 4PBDEs = 9.6 ng g (2.7 ng g 1 lipid) and 2009 (2.6 ng g 1 lipid). In human blood serum samples collected from the Australian population, PBDE concentrations did not vary greatly (p = 0.441) from 2002/03 to 2008/09. Continued monitoring including both human milk and serum for HBCD and PBDEs is required to observe trends in human body burden of HBCD and PBDEs body burden following changes to usage. Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction Brominated flame retardants including hexabromocyclododecane (HBCD) and polybrominated diphenyl ethers (PBDEs) ⇑ Corresponding author at: Medical Radiation Sciences, Queensland University of Technology, Brisbane 4001, Australia. E-mail address: [email protected] (Leisa-Maree L. Toms). 0045-6535/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.chemosphere.2012.05.053
are described as cost effective and highly efficient ways to reduce flammability and therefore potentially reduce the harm to humans caused by fires. HBCD has been used since the 1960s (Persistent Organic Pollutants Review Committee, 2011) in products such as upholstered textiles, rigid form plastics and polystyrene foam used in baby car seats (NICNAS, 2005a,b). The commercial HBCD product usually contains three steroisomers alpha (a-), beta (b-) and gamma (c-) at approximately
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6%, 8% and 80% (European Flame Retardants Association, 2009). PBDEs were produced as three commercial formulations: penta-BDE, octa-BDE and deca-BDE. The penta-BDE product was used mainly in flexible polyurethane foam for mattresses and cushioning, octa-BDE in the plastics industry in computer casings and monitors and deca-BDE in high impact polystyrenes and other materials for electronic and electrical appliances, the automotive industry, construction and building applications as well as textiles (ATSDR, 2004). Both HBCD and PBDEs are additive flame retardants and can therefore leach or volatilise from products and enter the environment and humans. Usage of both HBCD and PBDEs has changed over recent years with the inclusion of penta-BDE and octa-BDE into the annex of the Stockholm Convention (Stockholm Convention on POPs, 2010) and the voluntary phase out of deca-BDE in North America and Europe (Bromine Science and Environmental Forum, 2010). Unrestricted HBCD use continues in Australia and is not limited by EU regulations (European Chemical Industry Council accessed 20/9/09). The most recent data available shows that the importation of HBCD raw product into Australia increased by 78% between 1998/99 and 2003/04 (NICNAS, 2005a,b) while available information on raw product of penta- and octa-BDE indicates that no import of either chemical has occurred into Australia since mid 2005 (NICNAS, 2007). The commercial product HBCD has a high bioaccumulative and biomagnification potential (Vorkamp et al., 2011) and it is currently under consideration for inclusion in the Stockholm Convention on persistent organic pollutants (Birnbaum and Bergman, 2010). Data on human health effects of both HBCD and PBDE exposure is limited. Eggesbo et al. (2011) reported no association between thyroid stimulating hormone and exposure within the exposure level recorded. Dorosh et al. (2010) used human breast cancer cell lines and reported that HBCD at higher concentrations displayed oestrogenic properties and therefore has the potential to disrupt the endocrine system. Human data show PBDE concentrations in human milk to be associated with congenital cryptorchidism (Main et al., 2007); and lower birth weight, length and chest circumference (Chao et al., 2007). Reduced fecundability was found to be associated with PBDE exposure in women (Harley et al., 2010). While extensive studies have been conducted on the human body burden, sources and exposure pathways of PBDEs (e.g. Toms et al., 2007, 2008, 2009a, 2009b), data on HBCD is still limited. In Australia, PBDE intake sources are food (Food Standards Australia and New Zealand, 2007; Shanmuganathan et al., 2011) and to a lesser extent, dust and air (Toms et al., 2008, 2009a, 2009b). Data from Europe and North America suggest human exposure to HBCD is also via food (Driffield et al., 2008; Roosens et al., 2009; Schecter et al., 2010; Goscinny et al., 2011) and dust (Abdallah et al., 2008; Roosens et al., 2009). In Australia, there is currently no data on HBCD in humans and only one report of low concentrations in marine species from Sydney Harbour (Losada et al., 2009). Due to the longevity of products containing HBCD and PBDEs and despite, or because, of changes in usage rates, these products will remain in use for some time with the potential to provide both primary and secondary sources to the environment and humans. Internationally, temporal trends of HBCD and PBDE in human samples are inconsistent. PBDE concentrations in humans in Europe (Fängström et al., 2008; Lignell et al., 2009) and Asia (Kakimoto et al., 2007) increased in the 1980s and early 1990s and have seemingly stabilized in the late 1990s and early 2000s have seemingly plateaued in recent years. In Ghana, PBDE concentrations increased from 2004 to 2009 while HBCD did not (Asante et al., 2011) and in Swedish human milk from 1996 to
399
2006 HBCD was below the limit of quantification in most samples (Lignell et al., 2009). The main objective of this study is to provide the first data on HBCD in the Australian population enabling international comparisons and temporal trend analysis to be made. We also compare PBDE concentrations from existing and newly obtained data from both human milk and blood serum collected over a similar time period PBDE body burden allowing a determination of the effectiveness of legislative changes to usage. The data are essential for future monitoring of HBCD and PBDE body burden trends in Australia and to determine if an assessment of sources and exposure pathways is warranted. 2. Materials and methods 2.1. Sample collection Individual human milk samples and human blood sera have been collected throughout Australia from 2001 to 2009 and 2002 to 2009, respectively. In addition, human milk samples collected in 1993 (Quinsey et al., 1995) were also available for analysis. The 2001–2009 human milk was collected from volunteering mothers throughout Australia who were: primiparous; baby aged two to eight weeks; exclusively breastfeeding; healthy pregnancy; and a resident of the area for the past five years, see Toms et al. (2007) for full details. Participants were recruited through maternal and child health clinics and by word-of-mouth. Individual samples were pooled based on geographical region and year of collection with 4–10 samples per pool. Where possible more than one pool was used for a specific time period, as follows: 1993 (2 pools); 2001; 2002/2003 (4 pools); 2003/2004; 2006; 2007/2008 (2 pools); and 2009. Since regional differences were not observed in a previous study of PBDEs in human milk in Australia, the current study did not assess results by region. Human blood serum samples (n = 9694 in 204 pools) were collected from surplus deidentified pathology samples through Sullivan Nicolaides Pathology primarily from South East Queensland, Australia. Blood serum samples were stratified by age; gender; and year of collection 2002/03 (n = 2474), 2004/05 (n = 2400), 2006/07 (n = 2420) and 2008/09 (n = 2400). Details of these studies have been published previously (Toms et al., 2008, 2009a, 2009b) with the exception of the 2008/09 samples. The University of Queensland Medical Research Ethics Committee approved the study of human milk (H/308NRCET/00) and human blood serum (2002000656). 2.2. Analysis Concentrations of HBCD and PBDEs in human milk were determined at the Department of Environmental Chemistry, IDAEA, CSIC, Barcelona, Spain by liquid chromatography-mass spectrometry (LC-MS-MS) and gas chromatography coupled to mass spectrometry working with negative ion chemical ionisation (GC-NCIMS), respectively with full details of the methodologies including HBCD diastereoisomer and enantiomeric analysis and PBDE analysis available in the Supporting Information. For HBCD, before extraction, samples were lyophilised, homogenized, and stored at 22 °C. Samples of 0.5 g dry weight (dw) of milk were spiked with 50 lL of the labeled standard a- and c-HBCD-d18 at 125 pg lL 1. Spiked samples were kept overnight to equilibrate. Extraction was carried out by the pressurised liquid extraction (PLE) method on a fully automated accelerated solvent extraction system (ASE 200, Dionex, Sunnyvale, CA, USA). An 11 mL extraction cell was loaded by inserting two celluloses followed by the human milk sample. The dead volume was filled with anhydrous sodium sulphate for residue analysis previously activated at 150 °C for 4 h
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3. Results and discussion
3.1.1. Diastereoisomeric and enantiomeric analysis The diastereoisomeric pattern showed a predominance of the a- and c-isomers, with the b-isomer being below the limit of quantification in all but sample #13 (Table 1). The contribution of the aand c-isomers in samples obtained between 1993 and 2006 was similar and in samples obtained from 2007 to 2009 showed a dominance of the a-isomer (from 54% to 84% of the total contribution) versus the c-isomer. This inconsistency in the diastereoisomeric pattern may be due to individual variability in metabolizing capacity or the frequency of HBCD exposure as well as more extensive metabolism of b- and c-HBCD diastereoisomers in organisms than a-HBCD. Differing diastereoisomeric patterns have also been observed with a-HBCD the most abundant stereoisomer in serum samples from Sweden (Weiss et al. (2006), Cananda (Ryan et al. (2006) and Japan (Kakimoto et al. (2007) while Johnson-Restrepo et al. (2008) reported that c-HBCD was the dominant isomer present in the US. HBCD enantiomeric analysis was carried out showing the presence of the two pairs of enantiomers, ( )a- and (+)a-, and ( )c- and (+)c-HBCD, see Supporting Information for further details. EF (enantiomeric fraction) corrected values were calculated for different samples. In the case of c-HBCD, it was observed that EF values are between 0.21 and 0.59, whereas EF for a-HBCD was between 0.32 and 0.61. Comparison of samples with standards indicated two samples were enriched with the (+)-a-HBCD enantiomer while one sample was higher in the ( )-a-HBCD enantiomer. This ( )-a-HBCD enrichment in human milk samples was previously observed by Eljarrat et al. (2009) in samples collected from Spain. It has been suggested that enrichment of the ( )-a-HBCD enantiomer in humans may be due to in vivo enantioselective metabolism/ excretion rather than ingestion of dust or diet (Roosens et al. (2009).
3.1. HBCD in human milk
3.2. PBDEs in human milk and human blood serum
In this first report of HBCD in the Australian population, this BFR was detected in 9 out of 13 human milk pools with the mean P (±standard deviation) concentration of HBCD (sum of a-, c- and b-HBCD) in all samples of 10.2 ± 5.2 ng g 1 lipid (Table 1).
P In human milk, the 4PBDE (sum of BDEs-47, -99, -100 and -153) concentrations ranged from 2.5 to 15.8 ng g 1 lipid across all collection periods (Table 1) with a mean (±standard deviation) of 12.5 ± 6.4 ng g 1 lipid. This average concentration is in
(Panreac Quimica S.A., Montcada i Reixac, Barcelona, Spain). Extraction conditions were as follow: dichloromethane/hexane (2:1) mixture as solvent extractor, temperature of 100 °C, pressure of 14 MPa, two static extractions of 5 min and 100% flush. After extraction, the crude extracts were concentrated to 3 mL and then subjected to a purification step via acid attack with concentrated H2SO4 (95–97% purity) (3 2 mL). Samples were finally concentrated to incipient dryness and redissolved with 50 lL of the labeled standard b-HBCD-d18 at 125 pg lL 1, prior to instrumental analysis by LC-MS-MS. The pools of human blood were analysed using gas chromatography high resolution mass spectrometry. The 2002/03 and 2004/ 05 pools were analysed at Eurofins, Hamburg, Germany as described previously (Toms et al., 2008) and the 2006/07 and 2008/ 09 pools were analysed at the Center for Disease Control (CDC), Atlanta, Georgia, USA as described previously (Sjodin et al., 2004a). Statistical analysis was undertaken using SPSS 17.0, Two tailed, Pearson’s (for normally distributed data) and Spearman’s (for nonnormally distributed data) correlation coefficients were determined to assess correlation between variables. ANOVA models (including age-group, gender, collection date, and their interaction effects) were fitted with F-tests used to determine whether there were any significant differences in the means of the dependent variable between the different categories of the independent variables. The P response/dependent variable in these ANOVAs was PBDE, which was the sum of the concentrations of BDE-47, -85, -99, -100, -153, -154 and -183, natural log transformed and the analyses were weighted to account for the different pool sizes. The conventional 5% cut-off was used to assess statistical significance of results.
Table 1 Concentration (ng g
⁄⁄
*
1
lipid) of PBDEs and HBCD in human milk by year of collection.
Code
Origin
Fat content*
BDE-28
BDE-47
BDE-100
BDE-99
BDE-154
BDE-153
BDE-183
1 2 3 4 5 6 7 8 9 10 11 12 13 14 LOD (ng g LOQ (ng g
Blanka 1993 1993 2001 2002/03b 2002/03c 2002/03d 2002/03e 2002/03f 2003/04 2006 2007/08g 2007/08h 2009
2.7 3.8 3.3 3.2 3.2 3.1 2.7 2.2 4.1 4.5 3.7 2.9 3.1 3.3
na nd nd nd nd nd nd nd nd nd nd nd nd nd 0.34 1.14
na 5.6 4.4 6.4 4.9 4.0 11.5 6.8 7.2 9.3 8.5 3.0 2.5 1.4 0.14 0.46
na 1.2 1.1 nq 0.5 nq 2.3 1.8 1.3 1.4 1.4 nd nq 1.2 0.12 0.40
na 3.5 5.1 2.7 1.8 1.5 4.5 2.7 3.7 2.8 1.7 0.6 0.9 0.6 0.07 0.23
na 1.9 1.2 1.1 nd nq 2.0 nq nq 1.7 nq nd nq nq 0.19 0.65
na 1.4 1.4 1.6 1.2 1.0 3.2 3.3 2.4 4.5 1.5 2.0 1.6 1.3 0.05 0.16
na nq 1.0 nd nq nd 2.1 3.0 2.0 nq nq nq nd nq 0.21 0.70
1 1
, lw) , lw)
P
4PBDEs
na 8.7 6.7 7.5 5.4 4.0 15.8 8.6 8.5 12.4 9.9 3.0 2.5 2.6
a-HBCD
b-HBCD
c-HBCD
Total HBCD
nq nq 10 nq 4.5 5.9 3.1 nq 4 nq 2.8 7.8 6.8 2.1 0.1 0.2
nd nd nd nq nd nd nq nd nq nq nd nq 3.6 nd 1.0 3.3
nq nq 9.2 nq 6.8 4.8 2.6 nq 6.6 nq 2.2 4.5 4.4 0.4 0.1 0.3
nq nq 19 nq 11 11 5.7 nq 11 nq 5 12 15 2.5
Above detection limit (0.1), but below limit of quantification (0.2); na – not assessed, nq – not quantified, nd – not detected, value following < is the limit of detection. a cows’ milk. b Brisbane. c duplicate of 2002/03 Brisbane. d Wollongong. e Melbourne. f Hunter Valley. g Brisbane pool 1. h Brisbane pool 2. Expressed as % (g fat g 1 milk 100).
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BDE-47 concentration (ng/g lipid)
agreement with a study of 17 pools collected from around AustraP lia in 2002/03 where the 4PBDE mean (±standard deviation) was 1 10 ± 2.9 ng g lipid. In the current study, concentrations across all pools for BDEs-47, -99, -100 and -153 ranged from 1.4 to 11.5, 0.6 to 5.1, not quantified to 2.3 and 1.0 to 4.5 ng g 1 lipid, respectively. These four congeners were detected in 100%, 100%, 69% and 100% of pools, respectively, while BDEs- 154 and -183 were detected in 38% and 31% of pools, respectively and BDE-28 was not detected. In human milk and human blood, BDE-47 dominated the congeP ner profile contributing around 60% and 50% to the 4PBDE concentration, respectively, followed in descending order by BDEs99, -153, and -100. BDE-209, in human blood (2002/03; 2004/05; and 2008/09 samples), was reported as not detected or close to the detection limit, but was not determined in the human milk samples. Overall, concentrations of PBDE congener were significantly correlated and HBCD isomers were correlated but in human milk P 2 0.555 which just 4PBDE and total HBCD were not with r = reached significance at p = 0.049. This suggests that sources and exposure for these two BFRs differ. In human blood, PBDEs were detected in all pools with the P 1 li4PBDEs for adults (>16 years) ranging from 5.6 to 30.3 ng g pid in 2002/03; 4.0–12.2 ng g 1 lipid in 2004/05; 5.5– 14.5 ng g 1 lipid in 2006/07 and 6.6–13.7 ng g 1 lipid in 2008/09. Across all collection periods, PBDE concentrations in human blood were highest in the youngest age groups and decreased until
60 40
2002/03 2004/05 2006/07
30
2008/09
around middle age (Fig. 1). Age was found to have a significant P effect on PBDE concentration, F(4, 112) = 57.242, p < 0.001), P and individuals <16 years were found to have the highest PBDE concentrations. The observed age trend is likely related to the half-lives of the chemicals (Geyer et al., 2004) and the exposure pathways with children having higher exposure due to hand-tomouth activities and exposure via bedding and clothing (Heffernan et al. 2011). Across all collection periods, gender was found to have P a significant effect on PBDE concentrations (F(1112) = 13.185, P p < 0.001), where males were found to have higher mean PBDE concentrations compared to females. 3.3. International comparison In comparison to PBDEs, much less information is available on the HBCD concentrations in human milk. The concentrations of total HBCD which ranged from nq to 19 ng g 1 lipid are below those found in studies from Spain nd – 188 ng g 1 lipid (Eljarrat et al., 2009), similar to those reported from Norway (1993–2001) and Canada but greater than concentrations reported from Europe (Norway 2001; Russia; France; Sweden), Asia (Japan; Phillipines; China) and America (USA; Mexico) (Table 2). PBDE concentrations in human milk are higher than those reported from Europe (Fürst, 2006; Ingelido et al., 2007; Raab et al., 2008) and Asia (Akutsu et al., 2003; Sudaryanto et al., 2008) but lower than in North America (Ryan et al., 2006; Schecter et al., 2006). For HBCD, the results from this study are in agreement with international data showing variability in both the diastereoisomeric and enantiomeric patterns and are indicative of individual differences in either exposure or metabolism of this chemical. PBDE congener profiles in this study with dominance of BDE-47, -99, -100 and -153 reflect that observed internationally. 3.4. Temporal trends
20
10
0 0
20
40
60
80
Mean age (years) Fig. 1. Concentrations of BDE-47 (ng g females combined by collection date.
1
lipid) by mean age (years) for males and
Table 2 HBCD concentrations in human milk from different countries (expressed in ng g
1
HBCD and PBDEs have both been in use for several decades but while penta- and octa-BDE use was banned in 2004 (NICNAS, 2005a,b), HBCD usage continues unrestricted. If human body burden reflects current usage an increase in concentrations in humans is expected while for PBDEs we would expect a plateau following the ban of product usage. HBCD concentrations by year of collection are depicted in Fig. 2. While the concentrations were highest in one of the two (pooled) samples collected in 1993 at 19 ng g 1 lipid, HBCD was not detected in the other sample from this period. The result for 2009 was similar to that from 2001 with varying levels detected in between. This may be due to the small
of lipid weight).
Country
Year
a-HBCD
b-HBCD
c-HBCD
Total HBCD
Positive (n)
Reference
Australia Sweden
1993–2009 2001 2002–2003 2001 1993–2001 nr 2002–2003 2002 1973–1988 1988–2006 2000–2002 2004 2005 2006–2007 2007
nq–10 nr nr nr nr nr 3.8 0.5 nd 0.43–1.9 Nr 0.13–2.0 nd–5 nd–122 nd–2.8
3.6 nr nr nr nr nr nr nr nd nd nr nd–0.46 nd nd nd
nq–9.2 nr nr nr nr nr nr nr nd nd–2.6 nr nd–1.9 nd nd–176 nd–0.46
nq–19 nd–2.4 nd–1.5 0.25–2.0 0.4–20 0.8–5.4 0.4–19 0.2–0.9 nd 0.43–4.0 nd–1.67 0.13–3.2 nd–5 nd–188 nr
9 (13) 12 (33) 24 (30) nr (9) 49 (85) 7(7) nr (8) nr (9) nr 11 (11) 11 (37) nr (33) 7 (23) 30 (33) nr (24)
Current study Aune et al., 2002 Lignell et al., 2009 Thomsen et al., 2003 Thomsen et al., 2005 Lopez et al. 2004 Ryan et al., 2006
Norway Mexico Canada USA Japan Russia Philippines France Spain China
nd: Below limit of detection; nr: not reported.
Kakimoto et al., 2007 Polder et al., 2008 Shi et al., 2009 Antignac et al., 2008 Eljarrat et al., 2009 Shi et al., 2009
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100 90 80 70
levels is warranted to evaluate the effectiveness or otherwise of Australian Government policy changes.
sum PBDEs (human blood serum) sum PBDEs (human milk) total HBCD
4. Conclusion
BFR concentration (ng/g lipid)
50
The presented data suggest that HBCD contamination has occurred since the early 1990s in the Australian population. Variable concentrations between pools were from a given year were apparent with differences of more than an order of magnitude observed, although this may be due to the small number of pools used. The use of human blood serum pools allowed an assessment of temporal trends using a large sample size for PBDEs, however, to date, the serum samples have not been analysed for HBCD. Continued monitoring over time with the use of large pools of human blood serum for PBDEs and HBCD is warranted to further assess and monitor the body burden of BFRs in the Australian population. An assessment of source or exposure data on HBCD from Australia would contribute valuable information to the investigation of HBCD body burden in Australia.
40
30
20
10
Acknowledgements 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10
19 98
19
96
97
19
95
19
19
93 19
19
94
0
Year of collection P Fig. 2. Concentration of HBCD and 4PBDEs (ng g human blood serum by year of collection.
1
lipid) in human milk and
number of samples in each pool where a highly contaminated sample may increase the result of the pool. Statistical analysis of the results is not possible due to the small number of samples in each year of collection, however, from the figure there is no visual trend in HBCD concentrations by year of collection. HBCD concentrations over time are compared with PBDE concentrations where in human milk there appears to be a trend with a peak around 2002/ P 03 and 2003/04 with 4PBDEs of 9.6 (mean) and 12.4 ng g 1 lipid, respectively, followed by a decrease to a mean of 2.7 ng g 1 lipid in 2007/08 and 2.6 in 2009 (Fig. 2). In the current study, using the example of BDE-47 in human blood, the results suggest the development of a temporal trend. A comparison of concentrations in the 2002/03 and 2008/09 collection data shows that the mean concentration of BDE-47 in the 2008/09 was lower for all age groups by about 10–60% (Fig. 1), but this was not statistically significant (p = 0.441). Similarly, for P PBDEs, no significant temporal trends were detected (F(3,87) = 0.370, p = 0.775) across the four collection periods. It is also evident that despite the relatively large number of subjects per pool (100 subjects per pool, except for 2006/07 where 30 subjects per pool was used), the variability between samples from the same strata, appears to overshadow any observed temporal trend. BDE-47 concentrations were separated and compared for adults >16 years (Supporting information Fig. 1A) and children 0–4 years (Supporting information Fig. 1B) and 5–15 years (Supporting information Fig. 1C). The data indicate no obvious changes in the BDE47 concentration in adults, however a decrease in the concentration is observable in children. Reports of PBDE temporal trends in human samples over the last 30 years are varied. Studies from Sweden, Norway and Japan show PBDE concentrations in humans peaked around the late 1990s (Meironyte Guvenius and Noren 2001; Darnerud et al., 2002; Akutsu et al., 2003; Thomsen et al., 2005) while in the US, concentrations have increased significantly between 1985 and 2002 (Sjodin et al., 2004b). These data are consistent with differences in European and North American government policy restricting the use of these chemicals. Further evaluation of Australian
The authors would like to thank: all of the mothers and babies who donated or attempted to donate their precious time and milk samples for this study; all of the local coordinators who assisted in the recruitment of participants and the subsequent collection and return of samples; all laboratory staff at Sullivan Nicolaides Pathology and the CDC. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention. The National Research Centre for Environmental Toxicology is co-funded by Queensland Health. This study was partly funded by the Department of Sustainability, Environment, Water, Population and Communities. Appendix A. Supplementary material Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.chemosphere. 2012.05.053. References Abdallah, M.A., Harrad, S., Covaci, A., 2008. Hexabromocyclododecanes and tetrabromobisphenol-A in indoor air and dust in Birmingham, UK: implications for human exposure. Environ. Sci. Technol. 42, 6855–6861. Akutsu, K., Kitagawa, M., Nakazawa, H., Makino, T., Iwazaki, K., Oda, H., Hori, S., 2003. Time-trend (1973–2000) of polybrominated diphenyl ethers in Japanese mother’s milk. Chemosphere 53, 645–654. Antignac, J.P., Cariou, R., Maume, D., Marchand, P., Monteau, F., Zalko, D., Berrebi, A., Cravedi, J.P., Andre, F., Le Bizec, B., 2008. Exposure assessment of fetus and newborn to brominated flame retardants in France: preliminary data. Mol. Nutr. Food Res. 52, 258–265. Asante, K.A., Adu-Kumi, S., Nakahiro, K., Takahashi, S., Isobe, T., Sudaryanto, A., Devanathan, G., et al., 2011. Human exposure to PCBs, PBDEs and HBCDs in Ghana: temporal variation, sources of exposure and estimation of daily intakes by infants. Environ. Int. 37, 921–928. ATSDR, 2004. Toxicological Profile for Polybrominated Biphenyls and Polybrominated Diphenyl Ethers. Department of Health and Human Services, US Public Health Service. Agency for Toxic Substances and Disease Registry. Aune, M., Barregård, L., Claesson, A., Danerud, P.O., 2002. Organic environmental pollutants in breast milk from Gothenburg, Sweden, 2001 Report 219 0108 to the Swedish EPA; The Swedish National Food Administration: Uppsala, Sweden, 2002. Available from:. Birnbaum, L.S., Bergman, Å., 2010. Brominated and Chlorinated flame retardants: the San Antonio statement. Environ. Health Perspect. 118. http://dx.doi.org/ 10.1289/ehp.1003088. Bromine Science and Environmental Forum, 2010. Brominated Flame Retardant Deca-BDE, Decabromodiphenyl Ether Fact sheet. (accessed 19.10.11.).
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Brominated flame retardants in the Australian population: 1993–2009 Leisa-Maree L. Toms a,b,⇑, Paula Guerra d, Ethel Eljarrat d, Damià Barceló d, Fiona A. Harden a, Peter Hobson e, Andreas Sjodin f, Elizabeth Ryan c, Jochen F. Mueller c a
Medical Radiation Sciences, Queensland University of Technology, Brisbane, Australia Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia c The University of Queensland, National Research Centre for Environmental Toxicology (Entox), Brisbane, Australia d Department of Environmental Chemistry, IDAEA, CSIC, Barcelona, Spain e Sullivan Nicolaides Pathology, Brisbane, Australia f Centers for Disease Control and Prevention, Atlanta, USA b
h i g h l i g h t s " PBDE and HBCD concentrations assessed from 16 year period in Australia. " HBCD detected in 70% of human milk samples, no temporal trend apparent. " PBDEs detected in 100% of human milk and human blood serum samples. " Trend of decreasing PBDE serum concentrations in children from 2002/03 to 2008/09. " No PBDE trend in adults – youth body burden better reflects recent exposure.
a r t i c l e
i n f o
Article history: Received 23 November 2011 Received in revised form 5 May 2012 Accepted 19 May 2012 Available online 28 June 2012 Keywords: HBCD Hexabromocyclododecane PBDEs Brominated flame retardants Blood serum Breast milk
a b s t r a c t Brominated flame retardants, including hexabromocyclododecane (HBCD) and polybrominated diphenyl ethers (PBDEs) are used to reduce the flammability of a multitude of electrical and electronic products, textiles and foams. The use of selected PBDEs has ceased, however, use of decaBDE and HBCD continues. While elevated concentrations of PBDEs in humans have been observed in Australia, no data is available on other BFRs such as HBCD. This study aimed to provide background HBCD concentrations from a representative sample of the Australian population and to assess temporal trends of HBCD and compare with PBDE concentrations over a 16 year period. Samples of human milk collected in Australia from 1993 to 2009, primarily from primiparae mothers were combined into 12 pools from 1993 (2 pools); 2001; 2002/2003 (4 pools); 2003/2004; 2006; 2007/ P 2008 (2 pools); and 2009. Concentrations of HBCD ranged from not quantified (nq) to 19 ng g 1 lipid while a-HBCD and c-HBCD ranged from nq to 10 ng g 1 lipid and nq to 9.2 ng g 1 lipid. b-HBCD was P detected in only one sample at 3.6 ng g 1 lipid while 4PBDE ranged from 2.5 to 15.8 ng g 1 lipid. No temporal trend was apparent in HBCD concentrations in human milk collected in Australia from 1993 to 2009. In comparison, PBDE concentrations in human milk show a peak around 2002/03 (mean P 1 lipid) and 2003/04 (12.4 ng g 1 lipid) followed by a decrease in 2007/08 4PBDEs = 9.6 ng g (2.7 ng g 1 lipid) and 2009 (2.6 ng g 1 lipid). In human blood serum samples collected from the Australian population, PBDE concentrations did not vary greatly (p = 0.441) from 2002/03 to 2008/09. Continued monitoring including both human milk and serum for HBCD and PBDEs is required to observe trends in human body burden of HBCD and PBDEs body burden following changes to usage. Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction Brominated flame retardants including hexabromocyclododecane (HBCD) and polybrominated diphenyl ethers (PBDEs) ⇑ Corresponding author at: Medical Radiation Sciences, Queensland University of Technology, Brisbane 4001, Australia. E-mail address: [email protected] (Leisa-Maree L. Toms). 0045-6535/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.chemosphere.2012.05.053
are described as cost effective and highly efficient ways to reduce flammability and therefore potentially reduce the harm to humans caused by fires. HBCD has been used since the 1960s (Persistent Organic Pollutants Review Committee, 2011) in products such as upholstered textiles, rigid form plastics and polystyrene foam used in baby car seats (NICNAS, 2005a,b). The commercial HBCD product usually contains three steroisomers alpha (a-), beta (b-) and gamma (c-) at approximately
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6%, 8% and 80% (European Flame Retardants Association, 2009). PBDEs were produced as three commercial formulations: penta-BDE, octa-BDE and deca-BDE. The penta-BDE product was used mainly in flexible polyurethane foam for mattresses and cushioning, octa-BDE in the plastics industry in computer casings and monitors and deca-BDE in high impact polystyrenes and other materials for electronic and electrical appliances, the automotive industry, construction and building applications as well as textiles (ATSDR, 2004). Both HBCD and PBDEs are additive flame retardants and can therefore leach or volatilise from products and enter the environment and humans. Usage of both HBCD and PBDEs has changed over recent years with the inclusion of penta-BDE and octa-BDE into the annex of the Stockholm Convention (Stockholm Convention on POPs, 2010) and the voluntary phase out of deca-BDE in North America and Europe (Bromine Science and Environmental Forum, 2010). Unrestricted HBCD use continues in Australia and is not limited by EU regulations (European Chemical Industry Council accessed 20/9/09). The most recent data available shows that the importation of HBCD raw product into Australia increased by 78% between 1998/99 and 2003/04 (NICNAS, 2005a,b) while available information on raw product of penta- and octa-BDE indicates that no import of either chemical has occurred into Australia since mid 2005 (NICNAS, 2007). The commercial product HBCD has a high bioaccumulative and biomagnification potential (Vorkamp et al., 2011) and it is currently under consideration for inclusion in the Stockholm Convention on persistent organic pollutants (Birnbaum and Bergman, 2010). Data on human health effects of both HBCD and PBDE exposure is limited. Eggesbo et al. (2011) reported no association between thyroid stimulating hormone and exposure within the exposure level recorded. Dorosh et al. (2010) used human breast cancer cell lines and reported that HBCD at higher concentrations displayed oestrogenic properties and therefore has the potential to disrupt the endocrine system. Human data show PBDE concentrations in human milk to be associated with congenital cryptorchidism (Main et al., 2007); and lower birth weight, length and chest circumference (Chao et al., 2007). Reduced fecundability was found to be associated with PBDE exposure in women (Harley et al., 2010). While extensive studies have been conducted on the human body burden, sources and exposure pathways of PBDEs (e.g. Toms et al., 2007, 2008, 2009a, 2009b), data on HBCD is still limited. In Australia, PBDE intake sources are food (Food Standards Australia and New Zealand, 2007; Shanmuganathan et al., 2011) and to a lesser extent, dust and air (Toms et al., 2008, 2009a, 2009b). Data from Europe and North America suggest human exposure to HBCD is also via food (Driffield et al., 2008; Roosens et al., 2009; Schecter et al., 2010; Goscinny et al., 2011) and dust (Abdallah et al., 2008; Roosens et al., 2009). In Australia, there is currently no data on HBCD in humans and only one report of low concentrations in marine species from Sydney Harbour (Losada et al., 2009). Due to the longevity of products containing HBCD and PBDEs and despite, or because, of changes in usage rates, these products will remain in use for some time with the potential to provide both primary and secondary sources to the environment and humans. Internationally, temporal trends of HBCD and PBDE in human samples are inconsistent. PBDE concentrations in humans in Europe (Fängström et al., 2008; Lignell et al., 2009) and Asia (Kakimoto et al., 2007) increased in the 1980s and early 1990s and have seemingly stabilized in the late 1990s and early 2000s have seemingly plateaued in recent years. In Ghana, PBDE concentrations increased from 2004 to 2009 while HBCD did not (Asante et al., 2011) and in Swedish human milk from 1996 to
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2006 HBCD was below the limit of quantification in most samples (Lignell et al., 2009). The main objective of this study is to provide the first data on HBCD in the Australian population enabling international comparisons and temporal trend analysis to be made. We also compare PBDE concentrations from existing and newly obtained data from both human milk and blood serum collected over a similar time period PBDE body burden allowing a determination of the effectiveness of legislative changes to usage. The data are essential for future monitoring of HBCD and PBDE body burden trends in Australia and to determine if an assessment of sources and exposure pathways is warranted. 2. Materials and methods 2.1. Sample collection Individual human milk samples and human blood sera have been collected throughout Australia from 2001 to 2009 and 2002 to 2009, respectively. In addition, human milk samples collected in 1993 (Quinsey et al., 1995) were also available for analysis. The 2001–2009 human milk was collected from volunteering mothers throughout Australia who were: primiparous; baby aged two to eight weeks; exclusively breastfeeding; healthy pregnancy; and a resident of the area for the past five years, see Toms et al. (2007) for full details. Participants were recruited through maternal and child health clinics and by word-of-mouth. Individual samples were pooled based on geographical region and year of collection with 4–10 samples per pool. Where possible more than one pool was used for a specific time period, as follows: 1993 (2 pools); 2001; 2002/2003 (4 pools); 2003/2004; 2006; 2007/2008 (2 pools); and 2009. Since regional differences were not observed in a previous study of PBDEs in human milk in Australia, the current study did not assess results by region. Human blood serum samples (n = 9694 in 204 pools) were collected from surplus deidentified pathology samples through Sullivan Nicolaides Pathology primarily from South East Queensland, Australia. Blood serum samples were stratified by age; gender; and year of collection 2002/03 (n = 2474), 2004/05 (n = 2400), 2006/07 (n = 2420) and 2008/09 (n = 2400). Details of these studies have been published previously (Toms et al., 2008, 2009a, 2009b) with the exception of the 2008/09 samples. The University of Queensland Medical Research Ethics Committee approved the study of human milk (H/308NRCET/00) and human blood serum (2002000656). 2.2. Analysis Concentrations of HBCD and PBDEs in human milk were determined at the Department of Environmental Chemistry, IDAEA, CSIC, Barcelona, Spain by liquid chromatography-mass spectrometry (LC-MS-MS) and gas chromatography coupled to mass spectrometry working with negative ion chemical ionisation (GC-NCIMS), respectively with full details of the methodologies including HBCD diastereoisomer and enantiomeric analysis and PBDE analysis available in the Supporting Information. For HBCD, before extraction, samples were lyophilised, homogenized, and stored at 22 °C. Samples of 0.5 g dry weight (dw) of milk were spiked with 50 lL of the labeled standard a- and c-HBCD-d18 at 125 pg lL 1. Spiked samples were kept overnight to equilibrate. Extraction was carried out by the pressurised liquid extraction (PLE) method on a fully automated accelerated solvent extraction system (ASE 200, Dionex, Sunnyvale, CA, USA). An 11 mL extraction cell was loaded by inserting two celluloses followed by the human milk sample. The dead volume was filled with anhydrous sodium sulphate for residue analysis previously activated at 150 °C for 4 h
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3. Results and discussion
3.1.1. Diastereoisomeric and enantiomeric analysis The diastereoisomeric pattern showed a predominance of the a- and c-isomers, with the b-isomer being below the limit of quantification in all but sample #13 (Table 1). The contribution of the aand c-isomers in samples obtained between 1993 and 2006 was similar and in samples obtained from 2007 to 2009 showed a dominance of the a-isomer (from 54% to 84% of the total contribution) versus the c-isomer. This inconsistency in the diastereoisomeric pattern may be due to individual variability in metabolizing capacity or the frequency of HBCD exposure as well as more extensive metabolism of b- and c-HBCD diastereoisomers in organisms than a-HBCD. Differing diastereoisomeric patterns have also been observed with a-HBCD the most abundant stereoisomer in serum samples from Sweden (Weiss et al. (2006), Cananda (Ryan et al. (2006) and Japan (Kakimoto et al. (2007) while Johnson-Restrepo et al. (2008) reported that c-HBCD was the dominant isomer present in the US. HBCD enantiomeric analysis was carried out showing the presence of the two pairs of enantiomers, ( )a- and (+)a-, and ( )c- and (+)c-HBCD, see Supporting Information for further details. EF (enantiomeric fraction) corrected values were calculated for different samples. In the case of c-HBCD, it was observed that EF values are between 0.21 and 0.59, whereas EF for a-HBCD was between 0.32 and 0.61. Comparison of samples with standards indicated two samples were enriched with the (+)-a-HBCD enantiomer while one sample was higher in the ( )-a-HBCD enantiomer. This ( )-a-HBCD enrichment in human milk samples was previously observed by Eljarrat et al. (2009) in samples collected from Spain. It has been suggested that enrichment of the ( )-a-HBCD enantiomer in humans may be due to in vivo enantioselective metabolism/ excretion rather than ingestion of dust or diet (Roosens et al. (2009).
3.1. HBCD in human milk
3.2. PBDEs in human milk and human blood serum
In this first report of HBCD in the Australian population, this BFR was detected in 9 out of 13 human milk pools with the mean P (±standard deviation) concentration of HBCD (sum of a-, c- and b-HBCD) in all samples of 10.2 ± 5.2 ng g 1 lipid (Table 1).
P In human milk, the 4PBDE (sum of BDEs-47, -99, -100 and -153) concentrations ranged from 2.5 to 15.8 ng g 1 lipid across all collection periods (Table 1) with a mean (±standard deviation) of 12.5 ± 6.4 ng g 1 lipid. This average concentration is in
(Panreac Quimica S.A., Montcada i Reixac, Barcelona, Spain). Extraction conditions were as follow: dichloromethane/hexane (2:1) mixture as solvent extractor, temperature of 100 °C, pressure of 14 MPa, two static extractions of 5 min and 100% flush. After extraction, the crude extracts were concentrated to 3 mL and then subjected to a purification step via acid attack with concentrated H2SO4 (95–97% purity) (3 2 mL). Samples were finally concentrated to incipient dryness and redissolved with 50 lL of the labeled standard b-HBCD-d18 at 125 pg lL 1, prior to instrumental analysis by LC-MS-MS. The pools of human blood were analysed using gas chromatography high resolution mass spectrometry. The 2002/03 and 2004/ 05 pools were analysed at Eurofins, Hamburg, Germany as described previously (Toms et al., 2008) and the 2006/07 and 2008/ 09 pools were analysed at the Center for Disease Control (CDC), Atlanta, Georgia, USA as described previously (Sjodin et al., 2004a). Statistical analysis was undertaken using SPSS 17.0, Two tailed, Pearson’s (for normally distributed data) and Spearman’s (for nonnormally distributed data) correlation coefficients were determined to assess correlation between variables. ANOVA models (including age-group, gender, collection date, and their interaction effects) were fitted with F-tests used to determine whether there were any significant differences in the means of the dependent variable between the different categories of the independent variables. The P response/dependent variable in these ANOVAs was PBDE, which was the sum of the concentrations of BDE-47, -85, -99, -100, -153, -154 and -183, natural log transformed and the analyses were weighted to account for the different pool sizes. The conventional 5% cut-off was used to assess statistical significance of results.
Table 1 Concentration (ng g
⁄⁄
*
1
lipid) of PBDEs and HBCD in human milk by year of collection.
Code
Origin
Fat content*
BDE-28
BDE-47
BDE-100
BDE-99
BDE-154
BDE-153
BDE-183
1 2 3 4 5 6 7 8 9 10 11 12 13 14 LOD (ng g LOQ (ng g
Blanka 1993 1993 2001 2002/03b 2002/03c 2002/03d 2002/03e 2002/03f 2003/04 2006 2007/08g 2007/08h 2009
2.7 3.8 3.3 3.2 3.2 3.1 2.7 2.2 4.1 4.5 3.7 2.9 3.1 3.3
na nd nd nd nd nd nd nd nd nd nd nd nd nd 0.34 1.14
na 5.6 4.4 6.4 4.9 4.0 11.5 6.8 7.2 9.3 8.5 3.0 2.5 1.4 0.14 0.46
na 1.2 1.1 nq 0.5 nq 2.3 1.8 1.3 1.4 1.4 nd nq 1.2 0.12 0.40
na 3.5 5.1 2.7 1.8 1.5 4.5 2.7 3.7 2.8 1.7 0.6 0.9 0.6 0.07 0.23
na 1.9 1.2 1.1 nd nq 2.0 nq nq 1.7 nq nd nq nq 0.19 0.65
na 1.4 1.4 1.6 1.2 1.0 3.2 3.3 2.4 4.5 1.5 2.0 1.6 1.3 0.05 0.16
na nq 1.0 nd nq nd 2.1 3.0 2.0 nq nq nq nd nq 0.21 0.70
1 1
, lw) , lw)
P
4PBDEs
na 8.7 6.7 7.5 5.4 4.0 15.8 8.6 8.5 12.4 9.9 3.0 2.5 2.6
a-HBCD
b-HBCD
c-HBCD
Total HBCD
nq nq 10 nq 4.5 5.9 3.1 nq 4 nq 2.8 7.8 6.8 2.1 0.1 0.2
nd nd nd nq nd nd nq nd nq nq nd nq 3.6 nd 1.0 3.3
nq nq 9.2 nq 6.8 4.8 2.6 nq 6.6 nq 2.2 4.5 4.4 0.4 0.1 0.3
nq nq 19 nq 11 11 5.7 nq 11 nq 5 12 15 2.5
Above detection limit (0.1), but below limit of quantification (0.2); na – not assessed, nq – not quantified, nd – not detected, value following < is the limit of detection. a cows’ milk. b Brisbane. c duplicate of 2002/03 Brisbane. d Wollongong. e Melbourne. f Hunter Valley. g Brisbane pool 1. h Brisbane pool 2. Expressed as % (g fat g 1 milk 100).
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BDE-47 concentration (ng/g lipid)
agreement with a study of 17 pools collected from around AustraP lia in 2002/03 where the 4PBDE mean (±standard deviation) was 1 10 ± 2.9 ng g lipid. In the current study, concentrations across all pools for BDEs-47, -99, -100 and -153 ranged from 1.4 to 11.5, 0.6 to 5.1, not quantified to 2.3 and 1.0 to 4.5 ng g 1 lipid, respectively. These four congeners were detected in 100%, 100%, 69% and 100% of pools, respectively, while BDEs- 154 and -183 were detected in 38% and 31% of pools, respectively and BDE-28 was not detected. In human milk and human blood, BDE-47 dominated the congeP ner profile contributing around 60% and 50% to the 4PBDE concentration, respectively, followed in descending order by BDEs99, -153, and -100. BDE-209, in human blood (2002/03; 2004/05; and 2008/09 samples), was reported as not detected or close to the detection limit, but was not determined in the human milk samples. Overall, concentrations of PBDE congener were significantly correlated and HBCD isomers were correlated but in human milk P 2 0.555 which just 4PBDE and total HBCD were not with r = reached significance at p = 0.049. This suggests that sources and exposure for these two BFRs differ. In human blood, PBDEs were detected in all pools with the P 1 li4PBDEs for adults (>16 years) ranging from 5.6 to 30.3 ng g pid in 2002/03; 4.0–12.2 ng g 1 lipid in 2004/05; 5.5– 14.5 ng g 1 lipid in 2006/07 and 6.6–13.7 ng g 1 lipid in 2008/09. Across all collection periods, PBDE concentrations in human blood were highest in the youngest age groups and decreased until
60 40
2002/03 2004/05 2006/07
30
2008/09
around middle age (Fig. 1). Age was found to have a significant P effect on PBDE concentration, F(4, 112) = 57.242, p < 0.001), P and individuals <16 years were found to have the highest PBDE concentrations. The observed age trend is likely related to the half-lives of the chemicals (Geyer et al., 2004) and the exposure pathways with children having higher exposure due to hand-tomouth activities and exposure via bedding and clothing (Heffernan et al. 2011). Across all collection periods, gender was found to have P a significant effect on PBDE concentrations (F(1112) = 13.185, P p < 0.001), where males were found to have higher mean PBDE concentrations compared to females. 3.3. International comparison In comparison to PBDEs, much less information is available on the HBCD concentrations in human milk. The concentrations of total HBCD which ranged from nq to 19 ng g 1 lipid are below those found in studies from Spain nd – 188 ng g 1 lipid (Eljarrat et al., 2009), similar to those reported from Norway (1993–2001) and Canada but greater than concentrations reported from Europe (Norway 2001; Russia; France; Sweden), Asia (Japan; Phillipines; China) and America (USA; Mexico) (Table 2). PBDE concentrations in human milk are higher than those reported from Europe (Fürst, 2006; Ingelido et al., 2007; Raab et al., 2008) and Asia (Akutsu et al., 2003; Sudaryanto et al., 2008) but lower than in North America (Ryan et al., 2006; Schecter et al., 2006). For HBCD, the results from this study are in agreement with international data showing variability in both the diastereoisomeric and enantiomeric patterns and are indicative of individual differences in either exposure or metabolism of this chemical. PBDE congener profiles in this study with dominance of BDE-47, -99, -100 and -153 reflect that observed internationally. 3.4. Temporal trends
20
10
0 0
20
40
60
80
Mean age (years) Fig. 1. Concentrations of BDE-47 (ng g females combined by collection date.
1
lipid) by mean age (years) for males and
Table 2 HBCD concentrations in human milk from different countries (expressed in ng g
1
HBCD and PBDEs have both been in use for several decades but while penta- and octa-BDE use was banned in 2004 (NICNAS, 2005a,b), HBCD usage continues unrestricted. If human body burden reflects current usage an increase in concentrations in humans is expected while for PBDEs we would expect a plateau following the ban of product usage. HBCD concentrations by year of collection are depicted in Fig. 2. While the concentrations were highest in one of the two (pooled) samples collected in 1993 at 19 ng g 1 lipid, HBCD was not detected in the other sample from this period. The result for 2009 was similar to that from 2001 with varying levels detected in between. This may be due to the small
of lipid weight).
Country
Year
a-HBCD
b-HBCD
c-HBCD
Total HBCD
Positive (n)
Reference
Australia Sweden
1993–2009 2001 2002–2003 2001 1993–2001 nr 2002–2003 2002 1973–1988 1988–2006 2000–2002 2004 2005 2006–2007 2007
nq–10 nr nr nr nr nr 3.8 0.5 nd 0.43–1.9 Nr 0.13–2.0 nd–5 nd–122 nd–2.8
3.6 nr nr nr nr nr nr nr nd nd nr nd–0.46 nd nd nd
nq–9.2 nr nr nr nr nr nr nr nd nd–2.6 nr nd–1.9 nd nd–176 nd–0.46
nq–19 nd–2.4 nd–1.5 0.25–2.0 0.4–20 0.8–5.4 0.4–19 0.2–0.9 nd 0.43–4.0 nd–1.67 0.13–3.2 nd–5 nd–188 nr
9 (13) 12 (33) 24 (30) nr (9) 49 (85) 7(7) nr (8) nr (9) nr 11 (11) 11 (37) nr (33) 7 (23) 30 (33) nr (24)
Current study Aune et al., 2002 Lignell et al., 2009 Thomsen et al., 2003 Thomsen et al., 2005 Lopez et al. 2004 Ryan et al., 2006
Norway Mexico Canada USA Japan Russia Philippines France Spain China
nd: Below limit of detection; nr: not reported.
Kakimoto et al., 2007 Polder et al., 2008 Shi et al., 2009 Antignac et al., 2008 Eljarrat et al., 2009 Shi et al., 2009
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100 90 80 70
levels is warranted to evaluate the effectiveness or otherwise of Australian Government policy changes.
sum PBDEs (human blood serum) sum PBDEs (human milk) total HBCD
4. Conclusion
BFR concentration (ng/g lipid)
50
The presented data suggest that HBCD contamination has occurred since the early 1990s in the Australian population. Variable concentrations between pools were from a given year were apparent with differences of more than an order of magnitude observed, although this may be due to the small number of pools used. The use of human blood serum pools allowed an assessment of temporal trends using a large sample size for PBDEs, however, to date, the serum samples have not been analysed for HBCD. Continued monitoring over time with the use of large pools of human blood serum for PBDEs and HBCD is warranted to further assess and monitor the body burden of BFRs in the Australian population. An assessment of source or exposure data on HBCD from Australia would contribute valuable information to the investigation of HBCD body burden in Australia.
40
30
20
10
Acknowledgements 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10
19 98
19
96
97
19
95
19
19
93 19
19
94
0
Year of collection P Fig. 2. Concentration of HBCD and 4PBDEs (ng g human blood serum by year of collection.
1
lipid) in human milk and
number of samples in each pool where a highly contaminated sample may increase the result of the pool. Statistical analysis of the results is not possible due to the small number of samples in each year of collection, however, from the figure there is no visual trend in HBCD concentrations by year of collection. HBCD concentrations over time are compared with PBDE concentrations where in human milk there appears to be a trend with a peak around 2002/ P 03 and 2003/04 with 4PBDEs of 9.6 (mean) and 12.4 ng g 1 lipid, respectively, followed by a decrease to a mean of 2.7 ng g 1 lipid in 2007/08 and 2.6 in 2009 (Fig. 2). In the current study, using the example of BDE-47 in human blood, the results suggest the development of a temporal trend. A comparison of concentrations in the 2002/03 and 2008/09 collection data shows that the mean concentration of BDE-47 in the 2008/09 was lower for all age groups by about 10–60% (Fig. 1), but this was not statistically significant (p = 0.441). Similarly, for P PBDEs, no significant temporal trends were detected (F(3,87) = 0.370, p = 0.775) across the four collection periods. It is also evident that despite the relatively large number of subjects per pool (100 subjects per pool, except for 2006/07 where 30 subjects per pool was used), the variability between samples from the same strata, appears to overshadow any observed temporal trend. BDE-47 concentrations were separated and compared for adults >16 years (Supporting information Fig. 1A) and children 0–4 years (Supporting information Fig. 1B) and 5–15 years (Supporting information Fig. 1C). The data indicate no obvious changes in the BDE47 concentration in adults, however a decrease in the concentration is observable in children. Reports of PBDE temporal trends in human samples over the last 30 years are varied. Studies from Sweden, Norway and Japan show PBDE concentrations in humans peaked around the late 1990s (Meironyte Guvenius and Noren 2001; Darnerud et al., 2002; Akutsu et al., 2003; Thomsen et al., 2005) while in the US, concentrations have increased significantly between 1985 and 2002 (Sjodin et al., 2004b). These data are consistent with differences in European and North American government policy restricting the use of these chemicals. Further evaluation of Australian
The authors would like to thank: all of the mothers and babies who donated or attempted to donate their precious time and milk samples for this study; all of the local coordinators who assisted in the recruitment of participants and the subsequent collection and return of samples; all laboratory staff at Sullivan Nicolaides Pathology and the CDC. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention. The National Research Centre for Environmental Toxicology is co-funded by Queensland Health. This study was partly funded by the Department of Sustainability, Environment, Water, Population and Communities. Appendix A. Supplementary material Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.chemosphere. 2012.05.053. References Abdallah, M.A., Harrad, S., Covaci, A., 2008. Hexabromocyclododecanes and tetrabromobisphenol-A in indoor air and dust in Birmingham, UK: implications for human exposure. Environ. Sci. Technol. 42, 6855–6861. Akutsu, K., Kitagawa, M., Nakazawa, H., Makino, T., Iwazaki, K., Oda, H., Hori, S., 2003. Time-trend (1973–2000) of polybrominated diphenyl ethers in Japanese mother’s milk. Chemosphere 53, 645–654. Antignac, J.P., Cariou, R., Maume, D., Marchand, P., Monteau, F., Zalko, D., Berrebi, A., Cravedi, J.P., Andre, F., Le Bizec, B., 2008. Exposure assessment of fetus and newborn to brominated flame retardants in France: preliminary data. Mol. Nutr. Food Res. 52, 258–265. Asante, K.A., Adu-Kumi, S., Nakahiro, K., Takahashi, S., Isobe, T., Sudaryanto, A., Devanathan, G., et al., 2011. Human exposure to PCBs, PBDEs and HBCDs in Ghana: temporal variation, sources of exposure and estimation of daily intakes by infants. Environ. Int. 37, 921–928. ATSDR, 2004. Toxicological Profile for Polybrominated Biphenyls and Polybrominated Diphenyl Ethers. Department of Health and Human Services, US Public Health Service. Agency for Toxic Substances and Disease Registry. Aune, M., Barregård, L., Claesson, A., Danerud, P.O., 2002. Organic environmental pollutants in breast milk from Gothenburg, Sweden, 2001 Report 219 0108 to the Swedish EPA; The Swedish National Food Administration: Uppsala, Sweden, 2002. Available from:
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hexabromocyclododcane.